Excavations have been going on for a few months in the back (west side) of the Western Wall plaza. The Israel Antiquities Authority has a brief description of the finds so far. In short, they are excavating a building complex from the Mamluk and Ottoman periods that consists of several vaults.
This is a view from near the Western Wall towards the excavations, which are located just to the left (south) of the police station.
The excavations began in April, before construction of a building in this location.